The present invention relates to the field of robotics. More particularly, the invention relates to a method and associated software for generating robot motion coordinates for a coating machine.
Reference is made to U.S. Pat. Nos. 5,645,884 and 5,957,263, the entire disclosures of which hereby are incorporated by reference.
A machine has been used in the past to program robotic machines (referred to as robots below) to effect various functions. Initially, the setup of these functions can be a tedious process, as the robot must be programmed for each motion. An exemplary method of programming a robot is to manually operate the robot through the required motions while storing information representing those motions in memory.
A motion is defined by selecting a start location and an end location and typically, this process is accomplished using a teach pendant. In general, a teach pendent is a hand held control station which includes several control functions for each axis of motion, such as jog forward, jog reverse and teach. Using the teach pendant, the robot is positioned in space at the desired start location via the jog forward and jog reverse functions. Once in the desired location, the teach button is pressed to instruct the robot to retain the present location in memory. The robot is then jogged to the second location in space and the teach button is pressed, storing the second location into memory.
If the move is a simple straight line, then the process is complete. In most coating applications, however, this is not the case. Typically, the object has various curves, corners, crevices, humps, etc. that require precise positioning of the robot in order to achieve a quality coating. Thus, depending on the specific contour of the object, the process of teaching the robot each start and end location can be very tedious and time consuming.
In addition to being a tedious process, another disadvantage to such programming is that in order to confirm that the robot motions are proper for a given task, it is necessary that the robot be operated to carry out the given task. Thus, for example, if the robot is used in a coating process, e.g., painting, electro-static coating, or some other process, the actual coating line must be operated at normal speed and process parameters to be sure that the motions carried out manually are producing a proper coating on, say, a given part. Exemplary parts might be the inside of an oven cavity, a motor housing, a computer monitor, a control panel, or some other device. Such programming on an operating coating line requires the coating line to be out of production. The programming process can take a very long time, sometimes hours, even days, and sometimes even weeks or longer to obtain a desired programming to carry out acceptable uniform coating.
One example of using a robot to coat an object is in a spray painting device used to spray a desired coating on the inside of an oven cavity. Typically the coating should be uniform. However, as the tool, such as the paint spray head, comes to a junction of two oven walls, excess paint may be applied as the paint head finishes one move along one wall toward the junction and then commences moving along the adjacent wall from the junction. To avoid excess paint accumulation, the spray volume may be reduced as the spray head reaches the junction and then increased as the spray head moves away from the junction. In conventional robotic machines using the teach pendant system, it is necessary for a skilled technician to work jointly with the painter, i.e., the person who operates the paint spraying robot equipment, to work together to make the final adjustments and do the programming. Thus, not only does it take substantial time to carry out the programming functions, but also additional personnel are required, thus, further adding to the cost for carrying out the coating process due to set up of the machine, and making adjustments from time to time as materials and conditions change, e.g., viscosity of material may change with temperature of the ambient surroundings and affect the coating, etc. There is a need in the art to reduce the time, effort and cost to set up a coating machine or the like and/or to program robots to carry out various functions. Plus, there is a need to reduce the number of persons and time required for the aforementioned programming adjustments, etc., and there also is a need to facilitate such programming and adjustments so that a painter, for example, will be able to make necessary adjustments without the need to call in a separate technician.
Accordingly, it would be desirable to develop an automated coating process wherein the robot motion is generated automatically based on the shape of the object, without the requirements for specialized robotic programming skills.
The above examples of robotics with respect to coating machines and the need for various improvements also apply to robotics as used with other instruments and so called effectuators or effectors, and, as is described below the present invention is applicable to all of these uses of robotics and the interfacing of robots and controls therefore with facile controls, control systems, interfaces and the like.
A method for generating a process trajectory is described, the method, comprising displaying a normalized image of an object on a display device of a computer system, the object including a surface that is to be processed using an end effector; providing a number of predefined trajectories in a memory of the computer system, each of the predefined trajectories defining a motion of the end effector to process a surface of one of a number of spatial definitions; and generating the process trajectory for the end effector to process the surface of the object by associating at least one of the predefined trajectories with the normalized image.
In another embodiment, the present invention provides for a program embodied in a computer-readable medium for generating a process trajectory, comprising code that generates a display of a normalized image of an object on a display device, the object including a surface that is to be processed using an end effector; a number of predefined trajectories, each of the predefined trajectories defining a motion of the end effector to process a surface of one of a number of spatial definitions; and code that generates the process trajectory for the end effector to process the surface of the object by facilitating an association of at least one of the predefined trajectories with the normalized image.
In yet another embodiment, the present invention provides for a system for generating a process trajectory, comprising a processor circuit having a processor and a memory; a trajectory generation system stored in the memory and executable by the processor. The trajectory generation system further comprises logic that generates a display of a normalized image of an object on a display device, the object including a surface that is to be processed using an end effector; a number of predefined trajectories, each of the predefined trajectories defining a motion of the end effector to process a surface of one of a number of spatial definitions; and logic that generates the process trajectory for the end effector to process the surface of the object by facilitating an association of at least one of the predefined trajectories with the normalized image.
In still another embodiment, the present invention provides for a system for generating a process trajectory, comprising means for displaying a normalized image of an object on a display device of a computer system, the object including a surface that is to be processed using an end effector; means for storing a number of predefined trajectories, each of the predefined trajectories defining a motion of the end effector to process a surface of one of a number of spatial definitions; and means for generating the process trajectory for the end effector to process the surface of the object by associating at least one of the predefined trajectories with the normalized image.